Automatic draft regulator for boilers



% ATTORNEY Dec. 11, 1928;

L. w. EGGLESTON AUTOMATIC DRAFT REGULATOR FOR BOILERS Filed Nov. 50, 1925 Patented Dec. 11, 1928.

UNITED STATES PTENT OFFICE.

LEWIS W. EGGLESTON, OFBUFFALO, NEVJ YORK, ASSIGNOR TO AMERICAN RADIATOR COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF NEW JERSEY.

AUTOMATIC DRAFT REGULATOR FOR BOILERS.

Application filed November My invention relates to improvements in heating apparatus; and the same has for its object more particularly to provide a simple, compact and efficient device for controlling the rate of fuel consumption in a boiler, furnace or similar apparatus. Further, said .invention has for its object to provide a temperature regulating device which is controlled by means responsive to conditions within the heating apparatus.

Further, said invention has for its object to provide a temperature regulating device which is capable of adustment to predetermine the temperature at which the heating apparatus is to be maintained.

Further, said invention has for its object to provide an arrangement in which the position of the damper operating mechanism may be adjusted relative to the device responsive to conditions within the boiler to predetermine the temperature at which said mechanism is to be actuated by said device.

Further, said invention has for its object to provide a draft regulator in which the adjustable means employed to predetermine the temperature at which the heating apparatus is to be maintained, will also serve to manually control the admission of air to said apparatus.

Further, said invention has for its object to provide a draft regulator in which the operating lever thereof is freely suspended and is maintained in open position by gravity to render the same very sensitive and readily responsive when actuated by the device responsive to conditions within the boiler.

Other objects and advantages will in part be obvious and in part be pointed out hereinafter.

To the attainment of the aforesaid objects and ends my invention, consists in the novel details of'construction, and in the combination, connection and arrangement of parts hereinafter more fully described and then pointed outin the claims.

In the accompanying drawings formingpart of this specification Figure 1 is a side view, partly broken away and sectioned, showing a boiler provided with a regulator embodying the principles of my invention;

Fig. 2 is a central vertical side sectional view through the draft regulator;

30, 1925. Serial No. 72,082.

Fig. 3 is a rear view of the regulator, and

Fig. 4; is an enlarged detail section on the line 1& of Fig. 2.

In said drawings there is shown a combined boiler and heater 10 comprising a hollow front section 11, a hollow back section 12, and a plurality of substantially loopshaped intermediate sections 13. The front section 11 is provided with the usual fuel opening having door 13 a slicing opening having a door 14, an ash-pit opening having a door 15, and adjacent to its top with a flue opening provided with a door 16.

Within the boiler, between the front and back sections 11 and 12, are arranged a plurality of grate bars 17 positioned side by side and longitudinally of theboiler. At the upper rear end the boiler is provided with a smoke outlet 18. In the back section 12, adjacent the bottom of the boiler, is provided an air supply inlet 19 which communicates with the interior of the boiler below the grate 17.

The back section 12, near the upper end thereof, is provided with a threaded opening 25 in which is secured a tubular member or sleeve 26. A thermostatic device comprising an outer casing 27 and an inner metallic bellows 28 ispositioned within the tubular member 26, the space between the casing 27 and the bellows 28 being filled with an operating fluid, such, for example, as kerosene, ether, or any other suitable volatile or expansible fluid. The outer end of said bellows is joined to the casing 27 to seal the space be tween them. At its inner end the bellows is provided with a head 29 having a charging tube 30 extending outwardly therefrom. .A tubular plunger 31 surrounding the tube 30. engages at its inner end the head 29 and extends outwardly through a bracket 32 threaded into the open outer end ofthe tubular member or sleeve 26, said bracket providing a bearing in which said tubular plunger 31 slides. The outer end of said plunger 31 is provided with a yieldable head 33 retained in position within the plunger 31 by means of the cap, 3 1 threaded upon the outer end of the plunger, and through which said head 33 projects. A coil spring 35 is interposed between the head 33 and an abutment 36 disposed within the tubular upper end between the ears 38 formed upon the member 32. At its lower end the lever 37 carries a damper plate 39 cooperating with the air inlet 9, and normally held in open position by gravity.

As long as the bellows is in its retracted position, the lever 37 will maintain the air inlet open and permit of the increased supply of air which results in an increase of temperature. When the temperature rises suliicicntly to contract the bellows, the member 33 and the upper end of the lever 37 move outwardlyiwhile the lower end of the lever moves inwardly to cause the plate 39 to seal the air inlet opening 19 until the rate of coml istion is reduced. The long arm of the lever 37 greatly magnifies the movement of the lower end thereof. A stop comprising a pin 40 secured upon a bracket 41 above the air inlet 19 may be provided to engage the lever 37 to limitthe outward movement of the lower end thereof, which carries the plate 39.

In order to control the damper plate so that it will open and close at any desired pre detern'iined temperature there is provided, in a boss or sleeve 42 formed on the upper end of the lever 37, a rotatable member l3 having a spiral groove 4: 1 therein, a screw or other projection 45 carried by the boss 12 cooperating with the spiral groove ll to cause relative movement of the lever 37 and the member 43 upon rotation of the latter. The member 43 has a handle 46 at the outer end thereof for actuating the same.

The outer end of the boss 12 has formed thereon a flange or plate 4L7 bearing suitable indications or calibrations 48 for assisting the operator in adjusting to the desired temperature, the handle l6 being provided with a pointer 4-9 cooperating with said calibrations, and also constituting a stop engageable with a cooperating stop 50 to limit the rotation of the member as in each direction. The inner end 51 of the member 4-3 constitutes an abutment movable or adjustable relative to the member 33 to vary the relative position thereof, and hence, to control the temcally closed at a lower predetermined temperature. if desired, the said inlet may be closed'manually by rotating the handle 46 clockwise until the pointer 49 engages the stop 50. As the handle is rotated counterclockwise a correspondingly longer movement of the head v33 will be required before the same engages the end 51 to actuate the lever, and, as the amount of movement of the head depends directly on the temperature, as the handle is moved counter-clockwise, correspondingly higher predetermined temperatures must be attained before the damper closes. hen the temperature is correspondingly reduced the damper plate will move away from inlet 19.

The spring 35 serves to normally maintain the heal 33 in its outer position, and permits of the yielding of said head when an unusual or undesirably large force is applied thereto which might otherwise rupture or damage the bellows Q8.

The lever 37 is freely suspended, and is extremely sensitive to variations of the responsive device. The lever is maintained in open position by gravity, obviating the use of springs, and adjustment thereof to predetermine the temperature of operating is made by varying the relative positions of the head 33 and the end 51 of the rotatable member 43, the same adjusting means also serving to manually control the admission of air through said inlet 19.

While the above description contemplates control of the draft in accordance with the temperature developed within the boiler, it will be apparent that said control may be made dependent upon the pressure in the boiler by merely removing the casing 27 and exposing the bellows 28 directly to said pres- It is to be noted that all the openings in the front of the heating apparatus are closed by doors which are preferably ground to fit tightly against or over said openings in order to prevent any admission of air to the interior of the apparatus, and that the primary air necessary to support combustion is admitted to the heating apparatus wholly through the air inlet 19, which is automatically controlled.

The above description illustrates the principles embodied in my invention, but it will be understood that various changes and modifications may be made within the scope of the invention as defined by the annexed claims.

Having thus described my said invention, what I claim and desire to secure by Letters Patent is:

1. The combination of a boiler having a main air supply inlet, with a closure for said inlet, means responsive to conditions within the boiler disposed above said inlet and having a plunger projecting outwardly therefrom, a sleeve surrounding said responsive means and securedto said boiler, a bracket on said sleeve, a lever pivot-ally suspended at its upper end from said bracket, and connected to said closure at its lower end, and an adjustable member carried by said lever at the upper end thereof and adapted to en gage said plunger for predetermining the temperature at which said closure is actuated by saidresponsive means, substantially as specified.

2. The combination of a boiler having a main air supply inlet, means responsive to conditions within the boiler disposed above said inlet and having a plunger projecting outwardly therefrom, a sleeve secured to said boiler and surrounding said responsive means, a bracket carried by said sleeve, a lever pivotally suspended at its upper end from said bracket, and carrying said closure at its lower end; said device normally maintaining said closure in open position by gravity, a boss on said lever above the pivot thereof having an indicating plate thereon, a threaded member disposed within said boss and adapted to engage said plunger; said threaded member upon rotation thereof being adjustable towards and away from said plunger for predetermining the temperature at which said closure is actuated by said responsive means, and for manually controlling the admission-of air through said air inlet, and an actuating member secured to said threaded member and cooperating with said indicating plate for assisting the operator in adjusting to the desired temperature, substantially as specified.

Signed at the city of New York, in the county and State of New York, this 28th day of November, one thousand nine hundred and twenty-five.

LEWIS W. EGGLESTON. 

